Oil Leak after RMS replacement

[lspann3525]

Not sure how helpful this is but a month after I did my AFM delete I had a couple drips of oil on my driveway, I could see it dripping down my front diff. I could never find out where it came from but whatever was happening stopped, I haven't had a drop of oil on my driveway for a year now...

Maybe wait and see if it was just leftover leak oil and see if it stops.

To see if the valley cover is leaking you would need to remove your intake manifold to inspect it properly. Also oil being low at the bottom of the dipstick is fine, just top it off. When you see no oil on your dipstick is when you start to get yourself into trouble.

My front diff is leaking too. There is an arm that is coming from that diff on the left side that looks like some type of mount it is wet.

I just would hate to dive into doing the valley cover and find out that my leak isn't coming from there.

 

[lspann3525]

did you do the oil pan gasket?

I'm pretty sure the gaskets like to seep in the corners. my truck hasn't but my car did.

bit of a hassle. if it's just a bit wet, I'd just driver it till it becomes a drip

Yes I replaced the oil pan gasket

 

[lspann3525]

I have a very high mileage 5.3 and have been chasing down oil leaks since I got the truck. It seems like when I fix one another one pops up. It has a lot of blowby. The valley cover was loose as a goose and I replaced that. Then the valve covers started leaking replaced those with the updated one. Then the lower end started to leak. Front seal is weeping. Could be a pan gasket? Bolts are all tight. Then I tried a bottle of the "miracle" rear main fix and it worked great for a week not one drop on the ground then all of a sudden it is leaking a quart a week onto the ground so I am pretty sure the rear main seal is sht the bed because of that stupid move. Still kicking myself in the ass for that one.

I don't want to invest in having the RMS replaced on a 350K motor so I am currently price shopping a replacement motor and saving for one. Just going to run it like it is unit then. But I am certainly am sick of the oil spots and stink.

Im going to try to find the updated valve covers too and see if that will help. When the rear main seal was removed the oil pan gasket molding got damaged so I removed the pan and replaced the gasket with a FEL-PRO. Made sure every bolt was torqued to spec.

 

[lspann3525]

You must be burning it.

In the fall of 2018 our new to us Yukon was leaking and burning 2oz of oil every 100 miles. Here is what all 8 of the spark plugs looked like at 130k miles.

https://f01.justanswer.com/ebrock63...il+Consumption,+MIL+ON,+Engine+Runs+Rough.pdf

I fixed it. I found out about GM technical service bulletin TSB 10-06-01-008M - So, I installed the new improved valve cover, did a piston/combustion chamber soak (although differently than the way the TSB says to do it) installed deflector on pressure relief valve. It immediately stopped burning and leaking oil.

Now it has 187k miles and is still not consuming any oil.
View attachment 402410
View attachment 402411
https://www.tahoeyukonforum.com/threads/valve-cover-change-cleanup.108604/
and
https://www.tahoeyukonforum.com/thr...tor-oil-consumption-tsb-10-60-10-008m.108493/
and
https://www.tahoeyukonforum.com/threads/rear-main-seal-job-pan-etc-07-yukon-denali-6-2.108334/
and
https://www.tahoeyukonforum.com/threads/engine-oil-pan-gasket-change-6-2-yukon-l92.108487/
and
https://www.tahoeyukonforum.com/threads/get-a-catch-can-before-any-mods.49716/page-52#post-1287883

Great info I remember when doin my rms and you posted something about that deflector and I looked over it.

 

[j91z28d1]

Yes I replaced the oil pan gasket

not to nit-picking I'm just curious. did you put rtv on the 4 corners? I used felpro as well and it sealed up well on my car. haven't had to do the truck but same thing. just much much easier than this 4wd haha.

 

[donjetman]

My front diff is leaking too. There is an arm that is coming from that diff on the left side that looks like some type of mount it is wet.

I just would hate to dive into doing the valley cover and find out that my leak isn't coming from there.

Stock motor mounts are liquid filled, fail, and leak?

Most folks here replace them with non liquid filled Hummer mounts, GM# 25847739.

 

[Geotrash]

Im going to try to find the updated valve covers too and see if that will help. When the rear main seal was removed the oil pan gasket molding got damaged so I removed the pan and replaced the gasket with a FEL-PRO. Made sure every bolt was torqued to spec.

It’s real hard to get that oil pan sealed up in the corners. I have some seepage on my 2012 after having the pan off a few times and even though the gasket is new and I used RTV in the corners, it still seeps.

 

[OR VietVet]

Sometimes the biggest problem with continued seepage after using sealant at the 4 corners, is not letting the sealant cure before running the engine.

 

[Dustin Jackson]

@lspann3525 Oh now that you say it I wonder if my drips were actually front diff fluid leaking from when I had to man handle it out and back into the tahoe.

 

[iamdub]

Well guys after replacing the rear main seal on my 2008 tahoe z71 5.3 250,000 miles the oil leak has returned. It's not pouring out oil like before but it is seeping somewhere I just hope not the RMS again. Im not getting any oil spots in my driveway but I did notice a very small amount of oil on the left and right side of the bellhousing where it meets the engine block. Its not a severe leak just a very small drip. On top of that I took a trip from Mississippi to Georgia which was about 1000 miles to and from. And when I made it home and I checked the oil and it was at the bottom of the oil dipstick right where the crosshatch starts. Im currently running 5w30 and plan to go to 10w30 just in case the engine is burning oil with all those miles. With the engine running im not able to see any oil leaks it just overtime. Wile under the truck I removed the access hole cover and it's clean as a whistle inside.

I have recently changed the following parts. Replaced RMS with Dorman Rear Cover with seal, Valve Cover Gasket, Crankshaft Sensor, Oil Pressure Switch/Screen. Even thou my oil read at the bottom of the oil dip stick the alert message stop engine has not appeared. After doing some more google on oil leaks I found a couple of threads saying the valley pan gasket could be leaking and it's a known issue with the trucks that have AFM.... Im having a hard time trying to identify if it's the valley pan anyone have any ideas on checking the valley pan?

Yes, there are plenty of other possible leak points other than the RMS. But, when you replaced it, did you align the cover properly? There's a bit of a science to it. Also, it has to be installed dry, as in, don't lube the crankshaft. This factor is isn't such a big deal but I wanted to mention it as an example of the particulars for the sealing of these engines.